USB-C was supposed to be this savior of all ports, a be-all-end-all of sorts, but so far, I'm honestly lost with the acronyms. USB-C, 3.0 and 3.1 and 3.2, USB-C PD, VESA DisplayPort Alternate Mode, USB SuperSpeed+, and so on... It's becoming increasingly impossible to tell what each one means and what you need to have on your device to make sure it supports fast charging, fast data transfers, external displays, and audio playback.

Here's one more for you to worry about: Digital Audio. If you want your Pixel 2 or Pixel 2 XL to play music on your third-party USB-C headphones, you need to make sure those support digital audio. (As opposed to what? I don't know, and I'm honestly not too keen on spending 3 hours looking into that. I'm sure commenters will answer this quickly.) The same goes for third-party USB-C to 3.5mm adapters: they need to support USB-C digital audio too.

Here is a handy list put together by Googler Orrin of all verified third-party headphones compatible with the new Pixel 2 phones:

Of course the list is limited to Made by/for Google headphones, and you shouldn't technically have any issues with any Bluetooth headphones so their inclusion in this list isn't necessary. But at least you know where to get started if you wanted USB-C headphones that are guaranteed to work with your new Pixel 2/2 XL.